Gurobi 5.0.1 (linux64) logging started Sat Dec  8 03:32:24 2012

Optimize a model with 555 rows, 540 columns and 1772 nonzeros
Presolve removed 53 rows and 30 columns
Presolve time: 0.01s
Presolved: 502 rows, 510 columns, 1652 nonzeros
Variable types: 337 continuous, 173 integer (173 binary)

Root relaxation: objective 4.622366e+04, 253 iterations, 0.00 seconds

    Nodes    |    Current Node    |     Objective Bounds      |     Work
 Expl Unexpl |  Obj  Depth IntInf | Incumbent    BestBd   Gap | It/Node Time

     0     0 46223.6640    0   88          - 46223.6640     -      -    0s
H    0     0                    85955.000000 46223.6640  46.2%     -    0s
     0     0 56318.9377    0   18 85955.0000 56318.9377  34.5%     -    0s
H    0     0                    68829.000000 56318.9377  18.2%     -    0s
     0     0 56645.1565    0   13 68829.0000 56645.1565  17.7%     -    0s
     0     0 56654.6313    0   11 68829.0000 56654.6313  17.7%     -    0s
     0     2 56656.9091    0   11 68829.0000 56656.9091  17.7%     -    0s
H   27    24                    57097.000000 56656.9091  0.77%   6.6    0s
*  136    86              29    57036.000000 56696.4456  0.60%   5.2    1s
*  159    54              22    56888.000000 56698.6172  0.33%   5.1    1s
   513   151     cutoff    9      56888.0000 56758.4650  0.23%   4.9    5s
*  638   152              32    56884.000000 56769.6449  0.20%   6.1    6s
*  713   121              31    56869.000000 56819.1643  0.09%   6.0    7s

Cutting planes:
  Flow cover: 8
  Flow path: 1

Explored 722 nodes (4701 simplex iterations) in 7.60 seconds
Thread count was 1 (of 16 available processors)

Optimal solution found (tolerance 1.00e-04)
Best objective 5.686900000000e+04, best bound 5.686770669589e+04, gap 0.0023%